msc: add TC_gsup_mt_sms_lu_delay for X36 (LU delay) timer

Change-Id: I74fa174ea649adb2112c8e471c0e339a2197a08d
Related: osmo-msc.git Ic519cab55d65e47b2636124427dab1a1d80fab78
Related: SYS#6913
diff --git a/msc/MSC_Tests.ttcn b/msc/MSC_Tests.ttcn
index 09004e8..3c707d1 100644
--- a/msc/MSC_Tests.ttcn
+++ b/msc/MSC_Tests.ttcn
@@ -3282,6 +3282,65 @@
 	f_vty_config(MSCVTY, "msc", "no sms-over-gsup");
 }
 
+/* Test X36 (LU delay) timer allowing to deliver MT SMS over the same connection */
+friend function f_TC_gsup_mt_sms_lu_delay(charstring id, BSC_ConnHdlrPars pars)
+runs on BSC_ConnHdlr {
+	var SmsParameters spars := valueof(t_SmsPars);
+
+	f_init_handler(pars);
+
+	/* We need to inspect GSUP activity */
+	f_create_gsup_expect(hex2str(g_pars.imsi));
+
+	/* Perform location update */
+	f_perform_lu(expect_clear := false);
+
+	/* Register an 'expect' for given IMSI (+TMSI) */
+	f_ran_register_imsi(g_pars.imsi, g_pars.tmsi);
+
+	var template GSUP_PDU mt_forwardSM_res := tr_GSUP_MT_FORWARD_SM_RES(
+		imsi := g_pars.imsi,
+		/* NOTE: MSC should assign RP-MR itself */
+		sm_rp_mr := ?
+	);
+
+	/* Some delay to make sure the connection remains alive */
+	f_sleep(0.5);
+
+	/* Submit a MT SMS on GSUP */
+	f_gsup_forwardSM_req(spars);
+
+	/* Wait for MT SMS on DTAP */
+	f_mt_sms_expect(spars);
+
+	/* Send RP-ACK and expect MT-forwardSM-Res on GSUP */
+	f_mt_sms_send_rp_ack(spars);
+	alt {
+	[] GSUP.receive(mt_forwardSM_res) {
+		log("RX MT-forwardSM-Res (RP-ACK)");
+		setverdict(pass);
+		}
+	[] GSUP.receive {
+		setverdict(fail, "Rx unexpected GSUP message");
+		mtc.stop;
+		}
+	}
+
+	f_expect_clear();
+}
+testcase TC_gsup_mt_sms_lu_delay() runs on MTC_CT {
+	var BSC_ConnHdlrPars pars;
+	var BSC_ConnHdlr vc_conn;
+	f_init();
+	pars := f_init_pars(92);
+	f_vty_config(MSCVTY, "msc", "sms-over-gsup");
+	f_vty_config(MSCVTY, "msc", "timer geran X36 2500"); /* 2.5s */
+	vc_conn := f_start_handler_with_pars(refers(f_TC_gsup_mt_sms_lu_delay), pars);
+	vc_conn.done;
+	f_vty_config(MSCVTY, "msc", "timer geran X36 0");
+	f_vty_config(MSCVTY, "msc", "no sms-over-gsup");
+}
+
 /* convert GSM L3 TON to SMPP_TON enum */
 function f_sm_ton_from_gsm(BIT3 ton) return SMPP_TON {
 	select (ton) {
@@ -7434,6 +7493,7 @@
 	execute( TC_gsup_mt_sms_rp_mr() );
 	execute( TC_gsup_mo_mt_sms_rp_mr() );
 	execute( TC_gsup_mt_multi_part_sms() );
+	execute( TC_gsup_mt_sms_lu_delay() );
 
 	execute( TC_lu_and_mo_ussd_single_request() );
 	execute( TC_lu_and_mt_ussd_notification() );